At present, the Light-Emitting Diode (LED) backlight circuit has become a new trend in backlight technology by virtue of its advantages of a light and thin structure, a low power consumption, a high light-emitting efficiency, a desirable color performance ability, and so on. The LED backlight circuits are increasingly selected to be the backlight circuits that are used in Liquid Crystal Display (LCD) and other display devices.
Each LED backlight circuit is provided with a plurality of LED backlight units, and each LED backlight unit comprises a plurality of LEDs that are in series connection with one another. In order to guarantee the normal work of the LED backlight circuit, the LED backlight driving circuit which is used for driving the LED backlight circuit comprises an open circuit detection module that is used for detecting an open circuit malfunction of the LED backlight unit, and a short circuit detection module that is used for detecting a short circuit malfunction of the LED backlight unit. It is discovered that, when the open circuit malfunction occurs to one LED backlight unit, the LED backlight driving circuit can detect that there is no current in the LED backlight unit. Then, the LED backlight driving circuit outputs a higher voltage to the LED backlight circuit, so as to determine whether the difference among the LED backlight units (for example, the changes of the impedance thereof) results in that the operating voltage of the LED backlight unit rises. When the voltage output by the LED backlight driving circuit rises to a certain extent, the short circuit detection module would detect incorrectly that the short circuit malfunction occurs to other LED backlight units to which the open circuit malfunction does not occur. Under such circumstances, the LED backlight driving circuit would receive a notification from the short circuit detection module, and then turn off the LED backlight units that are detected by the short circuit detection module incorrectly. Consequently, the whole LED backlight circuit cannot work normally.